[clang] [clang-tools-extra] [Clang] Implement CWG2813: Class member access with prvalues (PR #95112)

[via cfe-commits]

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@@ -124,21 +125,67 @@ void usage() {
 }
 }; // namespace p1771
 
-#ifdef EXT
-// expected-warning at 5 {{use of the 'nodiscard' attribute is a C++17 extension}}
-// expected-warning at 9 {{use of the 'nodiscard' attribute is a C++17 extension}}
-// expected-warning at 12 {{use of the 'nodiscard' attribute is a C++17 extension}}
-// expected-warning at 13 {{use of the 'nodiscard' attribute is a C++17 extension}}
-// expected-warning at 29 {{use of the 'nodiscard' attribute is a C++17 extension}}
-// expected-warning at 65 {{use of the 'nodiscard' attribute is a C++20 extension}}
-// expected-warning at 67 {{use of the 'nodiscard' attribute is a C++20 extension}}
-// expected-warning at 71 {{use of the 'nodiscard' attribute is a C++20 extension}}
-// expected-warning at 73 {{use of the 'nodiscard' attribute is a C++20 extension}}
-// expected-warning at 74 {{use of the 'nodiscard' attribute is a C++20 extension}}
-// expected-warning at 84 {{use of the 'nodiscard' attribute is a C++20 extension}}
-// expected-warning at 86 {{use of the 'nodiscard' attribute is a C++17 extension}}
-// expected-warning at 87 {{use of the 'nodiscard' attribute is a C++20 extension}}
-// expected-warning at 91 {{use of the 'nodiscard' attribute is a C++17 extension}}
-// expected-warning at 92 {{use of the 'nodiscard' attribute is a C++20 extension}}
-// expected-warning at 95 {{use of the 'nodiscard' attribute is a C++20 extension}}
+namespace discarded_member_access {
+struct X {
+  union {
+    int variant_member;
+  };
+  struct {
+    int anonymous_struct_member;
+  };
+  int data_member;
+  static int static_data_member;
+  enum {
+    unscoped_enum
+  };
+  enum class scoped_enum_t {
+    scoped_enum
+  };
+  using enum scoped_enum_t;
+  // cxx11-17-warning at -1 {{using enum declaration is a C++20 extension}}
+
+  void implicit_object_member_function();
+  static void static_member_function();
+#if __cplusplus >= 202302L
+  void explicit_object_member_function(this X self);
 #endif
+};
+
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Sirraide wrote:

This is missing tests for MS properties (though I’d maybe put those in a different file).

https://github.com/llvm/llvm-project/pull/95112